The purpose of this Core is to support he scientific projects by providing and maintaining safe and effective subject interface systems, which collectively include all aspects of the systems, which collectively include all aspects of the systems used to present stimuli, monitor responses and physiologic events, and minimize acoustic noise exposure and subject movement. These systems are essential to all of the scientific projects because fMRI research is predicted on the ability to stimulate the brain and control behavior in a very specific manner. The systems proposed will provide essential new services and capabilities to the scientific groups, or enhance the existing user interface. The new systems will be easier to use and compatible with a wide range of subjects than the systems currently used. Although the efforts associated with the following specific aims will result in systems primarily intended for human subjects, this work will also provide new or enhance systems for use with animal subjects. The first set of specific aims is focused on the development of subject interface systems, and includes developing a standardized system to control and monitor the subject interface systems; improving the capabilities of the scientific groups to deliver high quality visual, auditory, and other sensory stimuli; expanding the types of subject responses that can be monitored; extending the capabilities for monitoring physiologic events; and enhancing the capabilities provided at the Mock scanner facility for training subjects, and acquiring behavioral and psychophysical data in a simulated MRI environment. The second set of specific aims is focused on characterizing the acoustic noise inside a head gradient coil during fMRI and then using this information to attenuate the noise exposure to the subjects. Although the primary responsibility of this Core is the development of new or enhanced subject interface systems, the core also provides the scientific projects with support services that include maintaining the subject interface systems, and training users in both the safety issues associated with the subject interface systems, and the correct handling and operation of these systems.